The purpose of this project is to provide basic information about the determinants and functions of problem-solving in late adulthood. Focusing on problems adapted from Piaget's work with younger age groups, this research is attempting to identify patterns of concrete- and formal-thought usage across a series of novel and familiar tasks. Individual differences in performance are being studied in relation to age (middle-aged vs. older-adult), health status, and initial educational level. The results of the project should help to reduce current conflicts in the literature with regard to late-life "regression" in problem-solving and may be useful in identifying educational techniques for older learners. The primary goals of the current budget period are to complete the testing of the final 50 subjects, to analyze results, and to prepare and submit the findings for publication.